msg_from_context_pattern.h
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#ifndef RHEO_MSG_FROM_CONTEXT_PATTERN_H
#define RHEO_MSG_FROM_CONTEXT_PATTERN_H
# include "rheolef/msg_util.h"
namespace rheolef {
/*F:
NAME: msg_from_context -- gather (@PACKAGE@ @VERSION@)
DESCRIPTION:
Computes the receive compressed message pattern for gather
and scatter.
ALGORITHM:
msg_from_context_pattern
"input": the ownership distribution and the indexes arrays
| msg_size(0:nproc)
"output": the receive context (from) and an auxilliary array proc2from_proc
| from_proc(0:send_nproc-1), from_ptr(0:send_nproc),
| proc2from_proc(0:nproc-1)
begin
| i := 0
| from_ptr(0) := 0
| for iproc := 0 to nproc-1 do
| if msg_size(iproc) <> 0 then
| from_proc(i) := iproc
| from_ptr(i+1) := from_ptr(i) + msg_size(i)
| proc2from_proc(iproc) := i
| i := i+1
| endif
| endfor
end
NOTE:
At the end of the algorithm, we have i = send_nproc.
COMPLEXITY:
Complexity is O(nproc).
METHODS: @msg_from_context_pattern
AUTHORS:
LMC-IMAG, 38041 Grenoble cedex 9, France
| Pierre.Saramito@imag.fr
DATE: 6 january 1999
END:
*/
//<msg_from_context_pattern:
template <
class InputIterator1,
class OutputIterator1,
class OutputIterator2,
class OutputIterator3>
void
msg_from_context_pattern (
InputIterator1 msg_size, // nproc
InputIterator1 last_msg_size,
OutputIterator1 from_proc, // send_nproc
OutputIterator2 from_ptr, // send_nproc+1
OutputIterator3 proc2from_proc) // nproc
{
typedef typename std::iterator_traits<InputIterator1>::value_type Size;
Size iproc = 0;
Size i = 0;
Size ptr_val = 0;
(*from_ptr++) = ptr_val;
while (msg_size != last_msg_size) {
Size sz = (*msg_size++);
if (sz != 0) {
(*from_proc++) = iproc;
ptr_val += sz;
(*from_ptr++) = ptr_val;
(*proc2from_proc) = i;
i++;
}
proc2from_proc++;
iproc++;
}
}
//>msg_from_context_pattern:
} // namespace rheolef
#endif // RHEO_MSG_FROM_CONTEXT_PATTERN_H
rheolef
This file is part of Rheolef.
Definition: compiler_eigen.h:37
rheolef::msg_from_context_pattern
void msg_from_context_pattern(InputIterator1 msg_size, InputIterator1 last_msg_size, OutputIterator1 from_proc, OutputIterator2 from_ptr, OutputIterator3 proc2from_proc)
Definition: msg_from_context_pattern.h:72